New Research Probes the Criminal Mind

That's the suggestion of a new study by researchers at Beth Israel Deaconess Medical Center in Boston.

Ever since the 1966 University of Texas Tower mass shooting, which left 13 people dead and 31 others injured, researchers have been intrigued by the possible ties between brain abnormalities and criminal behavior.

In that case, the shooter, Charles Whitman, complained of headaches and personality changes before he went on his killing spree at the University of Texas at Austin. Whitman, who was killed during the shootout, was later found to have a brain tumor.

This new study was led by Dr. Richard Darby, now an assistant professor of neurology at Vanderbilt University in Nashville.

"Our results can help to understand how brain dysfunction can contribute to criminal behavior." And this "may serve as an important step toward prevention or even treatment," said Darby.

"However, the presence of a brain lesion cannot tell us whether or not we should hold someone legally responsible for their behavior. This is ultimately a question society must answer," said Darby, who was previously with Beth Israel Deaconess.

For the study, researchers mapped brain lesions in 17 people who exhibited criminal behavior only after developing the lesions. While the lesions in the patients were located in different brain regions, all were within a specific brain network.

"We found that this network was involved in moral decision-making in normal people, perhaps giving a reason for why brain lesions in these locations would make patients more likely to behave criminally," Darby said in a Beth Israel news release.

The researchers had similar findings in a separate group of 23 people where the appearance of brain lesions and the start of criminal behavior were thought to be linked but not confirmed.

Darby and his colleagues emphasized that not all people with brain lesions within this specific decision-making network will commit crimes. Genetic, environmental and social factors also play a role.

Previous research has found that the brains of some criminals have abnormalities. However, in most cases it's unclear whether the abnormalities are the cause, or the result, of criminal behavior, or simply a coincidence.

The study was published Dec. 18 in the journal Proceedings of the National Academy of Sciences.